The application of the thermochromic material VO2 is restricted by its high critical temperature of metal-insulator transition(MIT)at about 68 ℃,unfavorable color,short service life,and unsatisfactory modulation ratio between the summer season and the winter season [1,2].In this work,the critical temperatures and phase stabilities of transition metal doped VO2 were predicted by use of density functional theory(DFT)calculations.Firstly,we optimized the structures and calculated the formation enthalpies of all the transition metal doped VO2(M1).And then,the critical temperatures were associated with the structural changes upon doping in terms of lattice expansion and decreasing of β angle.From the figure below,it could be concluded that the dopants W,Mo,and Re,which are the most studied dopants,cause greatest lattice expansion and β angle decreasing to VO2(R).In addition,the stabilities of transition metal doped VO2(R)were predicted based on their decomposition enthalpies and entropies.Finally,scandium was proposed as a potential dopant for VO2 in view of balanced comprehensive performances and phase stability.